Can obesity be decreased in incremental steps?
Hill, J.O. 2009. Can a small-changes approach help address the obesity epidemic? A Report of the Joint Task Force of the American Society for Nutrition, Institute of Food Technologists, and International Food Information Council American Journal of Clinical Nutrition, 89, 477-84.
In his research paper, Hill notes that body weight and obesity are increasing in all segments of the population in most, if not all, countries around the world. Further, although most people are aware that a sedentary existence, combined with overeating, has negative health consequences, many are not able to make and sustain the changes to combat this way of life. Moreover, most people who do achieve weight loss goals regain the weight over time. Is it inevitable that our society will eventually be obese?
The “small changes” approach was originally conceived as a lifestyle strategy for making a few simple adjustments in everyday life to prevent gradual weight gain. This strategy has now evolved into a comprehensive approach consisting of small changes in diet (slightly fewer calories consumed with each meal daily) and physical activity (more physical activity throughout the day) to combat obesity. The concept is not that small changes will have greater impact than bigger weight-change approaches (such as accumulating 200–300 minutes of physical activity a week and/or reducing caloric expenditure by 500–1,000 calories per day), but that small changes are more easily sustainable by most people, as compared with these bigger weight-change approaches.
A 17-member task force from the American Society for Nutrition, the Institute of Food Technologists and the International Food Information Council was established to evaluate the efficacy of the small-changes obesity intervention. The task force elucidates five major reasons why this approach to combating obesity might succeed:
1. Small changes are more realistic to achieve and maintain than large changes.
Based on years of research and observation, the committee agreed that large behavioral and lifestyle changes are difficult to achieve and sustain. However, small changes—such as walking 2,000 more steps a day (about 100 extra kilocalories of energy expenditure) and making simple food substitutions (e.g., replacing a 12-ounce regular soda with a diet soda, saving 150 kilocalories)—are doable and maintainable.
2. Even small changes can have an important impact on body weight regulation.
Hill suggests that most of the U.S. population gradually gains weight over time, and that a very slight discrepancy between energy intake (diet) and energy output (exercise and physical activity) has created an “energy gap.” This gap is estimated at 100 or fewer kilocalories per day for most people, with about half that being stored in the body as fat (on average, people are gaining about 1–2.5 pounds of fat per year). Thus, affecting energy balance by 100 kilocalories per day (by a combination of reductions in energy intake and increases in physical activity) could prevent weight gain in most of the population, according to Hill.
3. Small, successful lifestyle changes can lead to increased self-efficacy.
Self-efficacy is a person’s belief that he or she is capable of performing in a certain manner (in this case, making small lifestyle changes) to attain certain goals (losing weight and preventing weight regain). The task force postulates that positive changes in self-efficacy (from success in the small-changes approach) might motivate people to even greater weight loss progress.
4. The small-changes approach can be applied to environmental forces.
Over time, business entities such as restaurants, food industries and fast-food establishments have created environmental cues through triumphant marketing (e.g., supersizing meal deals) that encourage excessive food intake. It is hoped that the small-changes approach can succeed in persuading these environmental forces to make slight adjustments to their offerings (e.g., by serving more snack packs and low-calorie healthy options).
5. The small-changes approach can become a unifying platform for the public and private sectors t work together to combat obesity.
The thought is that the public sector and businesses involved in food sales, distribution and preparation may eventually work together in a common effort to battle the obesity epidemic.
Several leading organizations and groups have embraced the small-changes approach. The U.S. Department of Health and Human Services has launched a small-changes initiative with television and radio commercials and a website (www.smallstep.gov). The approach is supported by the U.S. Surgeon General (www.surgeongeneral.gov/priorities/prevention/), which encourages families to take “small, manageable steps within their current lifestyle—versus drastic changes—to ensure long-term health.” The mission of the nonprofit organization America On the Move (http://aom 3.americaonthemove.org/) is “to improve health and quality of life by promoting healthful eating and active living among individuals, families, communities and society.” America On the Move recommends adding 2,000 extra steps to one’s daily routine and eating 100 fewer calories each day. The American Dietetic Association, the American Heart Association and the American Cancer Society now endorse the small-changes approach. Even some branches of the food industry are starting to “invest” in this small-changes strategy by offering some smaller, lower-caloric-density food portions.
Hill summarizes current organization guidelines, which now suggest that individuals need to engage in moderate-intensity physical activity a minimum of 30 minutes per day to maintain health, 60 minutes per day to prevent weight gain and 60–90 minutes per day to prevent weight regain (after the initial weight is lost). However, Hill adds that over the last decade only 26% of the population has been able to meet the minimum physical activity guidelines (30 minutes per day). In addition, he notes that an additional 2,000 steps per day, which is enough to burn about 100 extra kilocalories per day, would be sufficient for most people not to gain excess weight. The 17-member task force suggests that pedometers may be a very viable (and inexpensive) tool for increasing physical activity. Bravata et al. (2007) reviewed 26 studies in which pedometers were used to raise physical activity levels. The average increase in these studies was 2,491 steps per day, a 26.9% rise in physical activity. Hill notes that this is equivalent to walking an additional 20–25 minutes a day and contends that this is an excellent example of how small changes to physical activity habits can be successfully achieved.
At this time Hill points out that the small-changes approach has not been scientifically tested in population samples to determine its worthiness with dietary changes. He does note that Americans are consuming more reduced-fat milk, which could be considered a significant positive dietary change. Also, many Americans are now seeking foods without trans fatty acids. Hill states that a small-changes approach can be achieved with reductions in fat and/or sugar intake. For example, sugar-sweetened drink consumption has increased from 222 to 458 kilocalories per day over the past 25 years in the United States. One way food manufacturers can contribute to the small-changes strategy is by reducing the energy density (i.e., kilocalories) in some foods by just adding a little more fiber and water.
The report by the 17-member task force emphasizes that the small-changes approach can be effective at increasing physical activity, decreasing energy intake and reducing excessive weight gain. It also states that, given the “lack of success” with other weight loss approaches to lifestyle change, the small-changes approach surely deserves genuine attention.
Although the future of using small changes to combat the obesity epidemic is hard to predict, for exercise professionals this strategy and its practical application provide a new tool box of ideas to use with clients pursuing weight loss goals.